Fully automated and sensitive detection of EGFR exon 18, 19, 20 and 21 mutational status in <2.5 hrs from a single FFPE slice.

Abstract

e20519 Background: Current molecular testing for mutations and indels in EGFRexons 18, 19, 20 and 21 is still laborious and often requires > 5 days in specialized labs. Multiple slices of FFPE tissue are often needed. Lack of experience, time or tissue for molecular testing are among the reasons why patients are often deprived of the proper targeted therapies. Therefore, a fast and fully automated assay with minimal hands-on time which can handle small samples should allow laboratories to quickly generate EGFR testing results as part of their precision medicine report. Methods: Idylla is a fully integrated MDx platform that combines speed and ease of use with high sensitivity and high multiplexing capabilities. For EGFR testing, it overcomes the current problem of lack of tissue and the time-consuming step of processing FFPE tissue samples. After insertion of a single 5 µm FFPE slice containing ≥10% neoplastic cells into the cartridge, the complete process of liquefication, extraction, rtPCR, data analysis and reporting is fully automated and takes < 2.5 hours. The Idylla EGFR Mutation Assay (RUO) allows the sensitive detection of 50+ mutations including indels in exons 18, 19, 20 and 21. Results: The Idylla EGFR Mutation Assay (RUO) was tested with single FFPE slices from 280 clinical NSCLC samples with known mutations as analyzed by NGS and digital droplet PCR. It demonstrated excellent specificity and sensitivity with an overall percentage agreement of > 96% and a positive and negative percentage agreement of > 97% and > 95%, respectively. Analytical sensitivity was assessed using cell line derived materials embedded in paraffin containing defined ratios of mutants and dilutions thereof in a WT background. Allelic frequencies ranging from 1 to 10% were tested in 6-fold and showed analytical sensitivities of 1% for all except one target which showed a sensitivity of 5%. Turnaround time of a run was < 2.5 hours and hands-on time was < 2 min. Conclusions:The new and fully automated Idylla EGFR Mutation Assay (RUO) demonstrates excellent specificity, high sensitivity, ease of use combined with a fast turnaround time for complete testing of more than 50 relevant EGFR mutations on FFPE samples from NSCLC patients.